Bengaluru: In a mid-night drama, Congress-JD(S) alliance chief ministerial candidate HD Kumaraswamy on late Wednesday arrived at the Eagleton Resort in Bengaluru, where Congress and JD(S) MLAs are staying, while security was deployed at the residence of BJP's B.S. Yeddyurappa, ahead of his swearing-in as the Chief Minister of Karnataka on Thursday.

The development took place after Karnataka Governor Vajubhai Rudabhai Vala invited the single-largest party, the BJP, to form a government and prove majority within 15 days.

A letter by Governor Vala reads, "You (Yeddyurappa) have been elected as the leader of the BJP legislative party of Karnataka. I am also in receipt of your letter dated 15th May 2018 staking claim to form the government."

Later, Kumaraswamy, son of former prime minister H.D. Deve Gowda accused the Governor of encouraging horse-trading.

While calling the Governer's decision unconstitutional, Kumaraswamy said, "By giving 15 days time (to prove majority) Governor is encouraging horse-trading by BJP leaders, this is unconstitutional. We will discuss the future plan."

The Congress even approached the Supreme Court Chief Justice Dipak Misra for an urgent hearing on the matter.

The party said the Governor denigrated his office, trampled the Constitution and acted as a BJP puppet.

Following the comments against the Governor, BJP tore into the Congress for trying to teach it "lessons on the dignity of the Constitution."

"The party that blew up the constitution to shambles is teaching us the constitution, the party that imposed President rule the most number of times and weakened the democracy is giving us lessons on dignity of the Constitution," Union Minister Ravi Shankar Prasad said at a press conference in New Delhi.

Results of the Karnataka Assembly polls announced on Tuesday evening showed that the BJP won 104 seats, emerging as the single largest party, while the Congress and JD(S) bagged 78 and 37 seats, respectively.

Post the poll verdict, the Congress and the JD(S) announced their decision to form a coalition government in the state with 115 MLAs, just above the halfway mark of 112.

However, the Governor yesterday invited Yeddyurappa to form the government in the state and gave him 15 days to prove majority.